The present invention is generally related to data communications and, more particularly, is related to a Reed-Solomon (xe2x80x9cRSxe2x80x9d) decoder and method for minimizing or eliminating errors in data communication.
Communication of information in the form of digital data is quite commonplace in today""s society. There are many different communications channels that may be employed to facilitate such data communication. Such channels may include existing telecommunications networks, optical fiber networks, cellular networks, the Internet, wide area networks, local area networks, or other like media. It is often the case that the communications channels chosen do not provide a perfect medium to transfer data information, and for various reasons such as noise, interference, or other phenomena, errors may be introduced into the data stream transmitted across a particular channel.
Many different approaches have been proposed to either reduce or eliminate errors in data communications. One such approach is to employ Reed-Solomon encoding/decoding. When employing Reed-Solomon encoding/decoding, data is transmitted in codewords which include a number of parity symbols along with the original data symbols. The parity symbols are generated using a Reed-Solomon encoder.
When using Reed-Solomon encoding, various numbers of parity symbols may be generated to allow a data system to correct up to a specific number of possible errors in the transmitted data. However, for each different number of total parity symbols generated, there is a unique Reed-Solomon generator polynomial with a specific number of coefficients employed. Thus, the typical Reed-Solomon encoder creates a specific number of parity symbols, which limits its usefulness if greater or fewer parity symbols are desired. Likewise, Reed-Solomon decoders are employed to correct errors in the transmission using the same specific number of parity symbols which limits its usefulness in the same manner.
The present invention provides a configurable Reed-Solomon decoder and method that addresses the above concerns. The configurable Reed-Solomon (RS) decoder comprises a parallel multiply accumulator having a data input to receive at least one RS codeword, the parallel multiply accumulator being configured to generate a syndrome array from the RS codeword. Also, the configurable RS decoder includes a Galois field computation unit coupled to the parallel multiply accumulator, and an RS decoder controller coupled to the parallel multiply accumulator and the Galois field computation unit, wherein the RS decoder controller controls the operation of the parallel multiply accumulator and the Galois field computation unit. The RS decoder may be configured for different numbers of symbols in the RS codewords, different numbers of parity symbols in the RS codewords, and for different modulation types employed in creating the RS codewords.
The present invention can also be viewed as providing a method for decoding a Reed-Solomon codeword in an RS decoder comprising the steps of: indicating an error correction capability configuration in the Reed-Solomon decoder; indicating a codeword length configuration in the Reed-Solomon decoder; indicating a modulation type configuration in the Reed-Solomon decoder; generating a syndrome array from the RS codeword based upon the error correction capability, codeword length, and modulation type configurations; and performing a number of calculations associated with a plurality of Reed-Solomon decoding algorithms based upon the error correction capability, codeword length, and modulation type configurations.
A significant advantage of the present invention is that it is highly configurable to implement Reed-Solomon decoding for different data communications applications, etc. Specifically, the Reed-Solomon decoder of the present invention may be configured to decode Reed-Solomon codewords having various numbers of parity symbols and data symbols. The present invention is also economical in that it requires a minimum number of logical components to implement and is power efficient, while at the same time being highly configurable. Other advantages of the invention are that it is simple in design, user friendly, robust and reliable in operation, and easily implemented for mass commercial production. The present invention is, for example, advantageously employed in various digital subscriber line modems that employ discrete multitone (DMT) line codes, carrierless amplitude-phase (CAP) line codes, quadrature amplitude modulation (QAM) line codes, and others.
Other features and advantages of the present invention will become apparent to one with skill in the art upon examination of the following drawings and detailed description. It is intended that all such additional features and advantages be included herein within the scope of the present invention.